944 



THE URINARY BLADDER, 



THE UKINARY BLADDER. 



The urinary bladder (vesica urinaria) is a hollow membranous and 

 muscular viscus, which receives the urine poured into it through the ureters, 

 retains it for a longer or shorter period, and finally expels it through the 

 urethra. 



During infancy it is pyriform, and lies chiefly in the abdomen, but in the 

 adult it is situated in the pelvic cavity behind the pubes, and in the male, 

 in front of the rectum ; in the female, it is separated from the rectum by 

 the uterus and vagina. 



The size and shape of the bladder, its position in the abdomino-pelvic 

 cavity, and its relations to surrounding parts, vary greatly, according to its 

 state of distension or collapse. When quite empty, the bladder lies deeply in 

 the pelvis, and in a vertical antero-posterior section presents a triangular ap- 

 pearance, being flattened before and behind, having its base turned downwards 



Fig. 664. 



Fig. 664. LATERAL VIEW OP THE VISCERA OF THE MALE PELVIS (after Quain). i 



The left os ilium has been disarticulated from the sacrum, the spinous process of the 

 ischium cut through, and the pubes divided to the left of the symphysis ; a, the bladder; 

 6, b', the rectum ; c, membranous part of the urethra ; d t section of the left crus or 

 corpus cavernosum ; e, bulb of the spongy body of the urethra ; /, Cowper's gland; g, 

 section of the body of the pubes ; h t sphincter ani muscle ; *, part of the left vas 

 deferens ; m, articular surface of the sacrum ; n, divided spine of the ischium ; o, 

 coccyx ; p, prostate gland ; r, r, peritoneum ; /, recto-vesical pouch ; u, left ureter ; ??, 

 left vesicula seminalis. 



and backwards, whilst its apex reaches up behind the symphysis pubis (fig. 

 601). The surfaces named anterior and posterior have thus a considerable 

 inclination. When moderately full, it is still contained within the pelvic 

 cavity, and has a -rounded form ; but when completely distended, it rises 

 above the brim of the pelvis, and becomes egg-shaped ; its larger end, which 

 is called the base or inferior fundus, being directed towards the rectum 



